1. Field of the Invention
The invention generally relates to a micro fluidic module applicable to micro-electromechanical devices, and particularly relates to a micro fluidic module having a consistent fluid flow.
2. Related Art
New technologies are fast developed and greatly facilitate the convenience of modern livings. Developments of micro electromechanical systems are especially a trend of new electronic and mechanical devices. In accompany with developments in semiconductor and information electronic industries, electronic products are getting lighter, thinner, shorter and smaller. The components and manufacturing facilities are also getting more tiny and precise. The manufacturing technologies are aiming at high precision, high density, high speed, intelligence and micro-miniature. The “next generation manufacturing technology” for the new century industries mainly includes two aspects. They are nano technology and micro electromechanical systems (MEMS). The fore one is the technology for manufacturing in the range of 102 nm˜10−1 nm; the next is to apply nano technology for making microelements and components and integrating systems with microelectronic circuits and controllers.
In the micro fluidic technology, common-used micro fluidic devices, such as ink jet print head, injector or other injection elements and applications are getting more and more important. As shown in FIG. 1A, a conventional micro fluidic channel element includes an ejection chamber 15 connected to a single channel 13 formed on a barrier 12. A heater boils the working fluid inside the chamber 15 and generates thermal bubble. The instant high pressure of the thermal bubble ejects a part of the working fluid outside through an unshown ejection nozzle and a part through the channel 13. After the thermal bubble dissipates, some working fluid provided by a reservoir 14 fills into the chamber 15 through the channel 13. So, the working fluid flows in two directions through the channel 13 that it comes out when ejection, and goes in when refilling.
As shown in FIG. 1B, a conventional micro fluid channel array, as disclosed by U.S. Pat. No. 6,042,222, includes several ejection chambers and channels. When any a chamber being activated by a heater 11 to eject working fluid out through the channel 13, the working fluid in the adjacent chambers 15 and channels 13 are interfered by fluidic “cross talk” that retards the refilling of the working fluid. The operating frequency of the channel is therefore hard to be increased. During the ejection process and refilling stage, the flows of working fluid are in opposite directions, the fluidic resistance slows the refilling and seriously influences the operating frequency of the ejector.